JP7445418B2 - battery cover - Google Patents

Description

The present invention relates to a battery cover.

Conventionally, a battery cover attached to a battery includes a side wall that covers the side surface of the battery, and the side wall includes a porous layer having heat insulating properties and a protective layer disposed on one side and the other side in the thickness direction of the porous layer. A battery cover has been proposed (for example, see Patent Document 1).

International Publication 2019/098231 Publication

In the battery cover as described in Patent Document 1 mentioned above, if there is a protruding part on the side surface of the battery, the battery cover may get caught on the protruding part, which may prevent the battery cover from being attached to the battery.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a battery cover that can be smoothly attached to a battery.

The present invention [1] includes a side wall that covers a side surface of the battery, and the side wall has a first surface layer in contact with the side surface of the battery, and a first surface layer of the battery in the thickness direction of the side wall. a second surface layer disposed on the opposite side of the side surface; a heat insulating layer disposed between the first surface layer and the second surface layer in the thickness direction; and a heat insulating layer disposed between the first surface layer and the heat insulating layer in the thickness direction. and a cushion layer disposed therebetween.

According to such a configuration, the side wall of the battery cover has a first surface layer that contacts the side surface of the battery, and a cushion layer that is disposed between the first surface layer and the heat insulating layer.

When attaching the battery cover to the battery, the side wall slides against the side of the battery at the first surface layer.

At this time, even if there is a protruding part on the side surface of the battery, the cushion layer placed inside the side wall (between the first surface layer and the heat insulating layer) deforms to fit the protruding part, so that the first surface layer protrudes. Prevents it from getting caught on parts.

Thereby, even if there is a protrusion on the side surface of the battery, the battery cover can smoothly get over the protrusion.

As a result, the battery cover can be smoothly attached to the battery.

Further, when the battery cover is completely attached to the battery, the elasticity of the cushion layer allows the first surface layer to reliably come into contact with the side surface of the battery.

Thereby, the space between the side surface of the battery and the heat insulating layer can be filled with the cushion layer and the first surface layer.

As a result, it is possible to suppress the air around the battery from flowing between the side surface of the battery and the heat insulating layer, and it is possible to suppress the transfer of ambient heat to the battery.

The present invention [2] includes the battery cover of the above [1], wherein the cushion layer has a 50% compression hardness lower than that of the heat insulation layer.

According to such a configuration, the cushion layer can be easily deformed while maintaining the shape of the heat insulating layer.

The present invention [3] provides the above [2], wherein the heat insulating layer has a 50% compression hardness of 10.0 kPa or more, and the cushion layer has a 50% compression hardness of 1.0 kPa or more and less than 10.0 kPa. ] Includes battery cover.

According to such a configuration, it is possible to more easily deform the cushion layer while maintaining the shape of the heat insulating layer.

The present invention [4] includes the battery cover according to any one of [1] to [3] above, wherein the thermal conductivity of the heat insulating layer is 0.045 W/(m·K) or less.

According to such a configuration, the heat insulating layer can suppress the transfer of ambient heat to the battery.

The present invention [5] includes the battery cover according to any one of [1] to [4] above, wherein each of the heat insulating layer and the cushion layer is made of a foam-based heat insulating material or a fiber-based heat insulating material.

According to such a configuration, the battery cover can be easily attached to the battery, and the heat insulation properties can be improved.

In the present invention [6], the battery has a first surface on which a terminal is disposed, a second surface spaced apart from the first surface in a first direction, and a surface between the first surface and the second surface in the first direction. and the side surface extending in the first direction, and the cushion layer extends from one end of the side wall to the other end in the first direction. 5].

According to such a configuration, when the battery cover is completely attached to the battery, the space between the side wall of the battery and the heat insulating layer is filled from one end of the side wall of the battery cover to the other end in the first direction. be able to.

In the present invention [7], the side wall has an inner surface that contacts the side surface of the battery in the thickness direction, and an outer surface that is arranged on the opposite side of the side surface of the battery with respect to the inner surface in the thickness direction. The battery cover according to any one of [1] to [6] above, wherein the outer surface has a recess that is recessed in the thickness direction and a bulge that swells out more than the recess in the thickness direction.

According to such a configuration, the side wall can be easily bent in the recessed part while ensuring heat insulation in the bulged part. Further, in the recessed portion, interference between members disposed around the battery and the side wall can be avoided.

The present invention [8] provides the battery according to the above [7], wherein when the battery cover is removed from the battery, the thickness of the heat insulating layer in the recess is thinner than the thickness of the heat insulating layer in the bulge. Including cover.

According to such a configuration, by molding the heat insulating layer, it is possible to form the recess while ensuring the thickness of the cushion layer.

The present invention [9] provides the above-mentioned [9], wherein when the battery cover is removed from the battery, the heat insulating layer in the recess is more compressed in the thickness direction than the heat insulating layer in the bulge. 7] or [8] battery cover included.

According to such a configuration, the recess can be easily formed by compressing the heat insulating layer.

The present invention [10] includes the battery cover according to any one of [7] to [9] above, wherein the recess extends along a corner of the battery.

According to such a configuration, the side wall can be bent according to the corner of the battery, and the side wall can be made to follow the side surface of the battery.

According to the battery cover of the present invention, it can be smoothly attached to a battery.

FIG. 1 is a perspective view of a battery equipped with a battery cover according to an embodiment of the present invention. FIG. 2 is a perspective view of the battery shown in FIG. 1. FIG. 3 is a perspective view of the battery cover shown in FIG. 1. FIG. 4 is a sectional view taken along line AA of the battery cover shown in FIG. FIG. 5 is a BB sectional view of the battery cover shown in FIG. 3. 6A and 6B are explanatory diagrams for explaining the method of manufacturing a battery cover, in which FIG. 6A shows a lamination process and FIG. 6B shows a molding process. FIG. 7 is a plan view of the laminate shown in FIG. 6B. 8A and 8B are explanatory diagrams for explaining how to attach the battery cover to the battery, and FIG. 8A shows how the battery cover is attached to the battery while deforming the cushioning material, and FIG. 8B indicates that the battery cover has been completely attached to the battery. FIG. 9 is an explanatory diagram illustrating a first modification, in which FIG. 9A is a perspective view of the battery cover of the first modification, and FIG. 9B is a CC of the battery cover shown in FIG. 9A. FIG. FIG. 10 is an explanatory diagram illustrating the second modification. FIG. 11 is an explanatory diagram illustrating a third modification. FIG. 12 is a plan view of a test piece for evaluating heat insulation properties. FIG. 13 is a DD cross-sectional view of the test piece shown in FIG. 12. FIG. 14 is a schematic configuration diagram of an evaluation device for evaluating heat insulation properties. FIG. 15 is a side view of the jig shown in FIG. 14, viewed from the opposite direction. FIG. 16 is a plan view of a test piece for evaluating wearability. FIG. 17 is a schematic configuration diagram of an evaluation device for evaluating wearability. FIG. 18 is an explanatory diagram for explaining a method for evaluating wearability.

As shown in FIG. 1, a battery cover 1 as an embodiment of the present invention is attached to a battery 100.

1. battery 100
The battery 100 will be described with reference to FIG. 2.

In this embodiment, battery 100 is a lead acid battery. Note that the battery 100 is not limited to a lead acid battery, and may be a secondary battery such as a lithium ion secondary battery.

Battery 100 has a substantially rectangular parallelepiped shape. The battery 100 includes a battery case 101, a lid 102, a positive plate (not shown), a negative plate (not shown), a positive terminal 103 as an example of a terminal, and a negative terminal 104 as an example of a terminal. Equipped with

Battery case 101 has an opening (not shown). The opening is arranged at one end of the battery case 101 in the first direction. Battery case 101 houses a positive electrode plate, a negative electrode plate, and an electrolyte.

The lid 102 is attached to one end of the battery case 101 in the first direction. The lid 102 closes the opening of the battery case 101.

A positive terminal 103 and a negative terminal 104 are attached to the lid 102. Positive electrode terminal 103 is electrically connected to the positive electrode. Negative electrode terminal 104 is electrically connected to the negative electrode. Negative electrode terminal 104 is arranged at a distance from positive electrode terminal 103 in the second direction. The second direction is orthogonal to the first direction.

The battery 100 has a first surface S1, a second surface S2, and a side surface S3. In this embodiment, the first surface S1 is the upper outer surface of the lid 102. The positive electrode terminal 103 and the negative electrode terminal 104 are arranged on the first surface S1. The second surface S2 is the lower outer surface of the battery case 101. That is, the second surface S2 is separated from the first surface S1 in the first direction. Side surface S3 is a side surface of battery case 101. The side surface S3 is arranged between the first surface S1 and the second surface S2 in the first direction. Side surface S3 extends in the first direction. In this embodiment, the side surface S3 includes a first side surface S31, a second side surface S32, a third side surface S33, and a fourth side surface S34.

The first side surface S31 is one outer surface of the battery case 101 in the third direction. The third direction is orthogonal to the first direction and the second direction. The first side surface S31 extends in the first direction and the second direction.

The second side surface S32 is the other outer surface of the battery case 101 in the third direction. The second side surface S32 extends in the first direction and the second direction.

The third side surface S33 is one outer surface of the battery case 101 in the second direction. The third side surface S33 extends in the first direction and the third direction. One end of the third side surface S33 in the third direction is connected to one end of the first side surface S31 in the second direction. A portion where one end of the third side surface S33 in the third direction and one end of the first side surface S31 in the second direction are connected is the corner C1. The other end of the third side surface S33 in the third direction is connected to one end of the second side surface S32 in the second direction. The corner C2 is a portion where the other end of the third side surface S33 in the third direction and one end of the second side surface S32 in the second direction are connected.

The fourth side surface S34 is the other outer surface of the battery case 101 in the second direction. The fourth side surface S34 extends in the first direction and the third direction. One end of the fourth side surface S34 in the third direction is connected to the other end of the first side surface S31 in the second direction. A corner C3 is a portion where one end of the fourth side surface S34 in the third direction and the other end of the first side surface S31 in the second direction are connected. The other end of the fourth side surface S34 in the third direction is connected to the other end of the second side surface S32 in the second direction. A portion where the other end of the fourth side surface S34 in the third direction and the other end of the second side surface S32 in the second direction are connected is a corner C4.

2. battery cover 1
Next, the battery cover 1 will be explained with reference to FIGS. 1 to 5.

As shown in FIG. 1, when the battery cover 1 is attached to the battery 100, the battery cover 1 covers the outer surface of the battery 100. When the battery cover 1 is attached to the battery 100, the battery cover 1 suppresses the transfer of ambient heat to the battery 100.

Note that the battery cover 1 may expose a part of the outer surface of the battery 100. In this embodiment, when the battery cover 1 is attached to the battery 100, the battery cover 1 covers the side surface S3 of the battery 100 and exposes the first surface S1 and the second surface S2 (see FIG. 2) of the battery 100. do. With the battery cover 1 attached to the battery 100, the battery cover 1 surrounds the battery 100.

(1) Shape of battery cover 1 As shown in FIG. 3, battery cover 1 has a cylindrical shape. The battery cover 1 extends in the first direction. The battery cover 1 includes a side wall 2. In this embodiment, the battery cover 1 consists of only the side wall 2. When the battery cover 1 is attached to the battery 100 (see FIG. 1), the side wall 2 covers the side surface S3 of the battery 100. In this embodiment, the side wall 2 includes a first side wall 2A, a second side wall 2B, a third side wall 2C, and a fourth side wall 2D.

The first side wall 2A is arranged at one end of the battery cover 1 in the third direction. The first side wall 2A extends in the first direction and the second direction. The first side wall 2A has a flat plate shape. With the battery cover 1 attached to the battery 100, the first side wall 2A covers the first side surface S31 (see FIG. 2) of the battery 100.

The second side wall 2B is arranged at the other end of the battery cover 1 in the third direction. The second side wall 2B is arranged at a distance from the first side wall 2A in the third direction. With the battery cover 1 attached to the battery 100, the second side wall 2B is arranged on the opposite side of the first side wall 2A with respect to the battery 100 in the third direction. The second side wall 2B extends in the first direction and the second direction. The second side wall 2B has a flat plate shape. With the battery cover 1 attached to the battery 100, the second side wall 2B covers the second side surface S32 (see FIG. 2) of the battery 100.

The third side wall 2C is arranged at one end of the battery cover 1 in the second direction. The third side wall 2C extends in the first direction and the third direction. The third side wall 2C has a flat plate shape. With the battery cover 1 attached to the battery 100, the third side wall 2C covers the third side surface S33 (see FIG. 2) of the battery 100. One end of the third side wall 2C in the third direction is connected to one end of the first side wall 2A in the second direction. The other end of the third side wall 2C in the third direction is connected to one end of the second side wall 2B in the second direction.

The fourth side wall 2D is arranged at the other end of the battery cover 1 in the second direction. The fourth side wall 2D is arranged at a distance from the third side wall 2C in the second direction. With the battery cover 1 attached to the battery 100, the fourth side wall 2D is arranged on the opposite side of the third side wall 2C with respect to the battery 100 in the second direction. The fourth side wall 2D extends in the first direction and the third direction. The fourth side wall 2D has a flat plate shape. With the battery cover 1 attached to the battery 100, the fourth side wall 2D covers the fourth side surface S34 (see FIG. 2) of the battery 100. One end of the fourth side wall 2D in the third direction is connected to the other end of the first side wall 2A in the second direction. The other end of the fourth side wall 2D in the third direction is connected to the other end of the second side wall 2B in the second direction.

Moreover, the side wall 2 has an inner surface S11 and an outer surface S12.

With the battery cover 1 attached to the battery 100, the inner surface S11 contacts the side surface S3 of the battery 100 (see FIG. 2) in the thickness direction of the side wall 2. In addition, in this embodiment, the "thickness direction" is the third direction in the first side wall 2A and the second side wall 2B. Further, in the third side wall 2C and the fourth side wall 2D, the "thickness direction" is the second direction.

When the battery cover 1 is attached to the battery 100, the outer surface S12 is arranged on the opposite side of the side surface S3 (see FIG. 2) of the battery 100 with respect to the inner surface S11 in the thickness direction.

Furthermore, the side wall 2 has edges 3A, 3B, outer bulges 4A to 4D as a plurality of bulges, a plurality of recesses 5A to 5D, and an inner bulge 6 (see FIG. 4). .

(1-1) Edges 3A, 3B
As shown in FIGS. 3 and 4, the edge 3A is arranged at one end (upper end) of the battery cover 1 in the first direction. The edge 3A extends over the entire circumference of the battery cover 1. In this embodiment, the edge 3A extends in the second direction on the first side wall 2A and the second side wall 2B, and extends in the third direction on the third side wall 2C and the fourth side wall 2D.

The edge 3B is spaced apart from the edge 3A in the first direction. The edge 3B is arranged at the other end (lower end) of the battery cover 1 in the first direction. Edge 3B, like edge 3A, extends over the entire circumference of battery cover 1.

(1-2) Outer bulges 4A to 4D
As shown in FIGS. 3 and 4, the plurality of outer bulges 4A to 4D are arranged between the edge 3A and the edge 3B in the first direction. Each of the plurality of outer bulges 4A to 4D swells outward from the edge 3A and the edge 3B in the thickness direction. When the battery cover 1 is attached to the battery 100 (see FIG. 8B), each of the plurality of outer bulges 4A to 4D has a side surface of the battery 100 with respect to the edge 3A and the edge 3B in the thickness direction. It bulges to the opposite side of S3 (see Figure 1).

As shown in FIGS. 3 and 5, the outer bulge 4A is arranged on the outer surface S12 of the first side wall 2A. The outer bulge 4B is arranged on the outer surface S12 of the second side wall 2B. The outer bulge portion 4C is arranged on the outer surface S12 of the third side wall 2C. The outer bulge 4D is arranged on the outer surface S12 of the fourth side wall 2D.

(1-3) Recesses 5A to 5D
As shown in FIG. 3, the plurality of recesses 5A to 5D are arranged between the edge 3A and the edge 3B in the first direction. The recess 5A is arranged at a connecting portion between the first side wall 2A and the third side wall 2C. The recess 5B is arranged at a connecting portion between the second side wall 2B and the third side wall 2C. The recessed portion 5C is arranged at a connecting portion between the first side wall 2A and the fourth side wall 2D. The recessed portion 5D is arranged at a connecting portion between the second side wall 2B and the fourth side wall 2D. Each of the plurality of recesses 5A to 5D extends in the first direction. When the battery cover 1 is attached to the battery 100, the recess 5A extends along the corner C1 (see FIG. 2), the recess 5B extends along the corner C2 (see FIG. 2), and the recess 5C extends along the corner C1 (see FIG. 2). The recess 5D extends along the corner C3 (see FIG. 2), and the recess 5D extends along the corner C4 (see FIG. 2).

As shown in FIG. 5, each of the plurality of recesses 5A to 5D is recessed from the outer surface S12 toward the inner surface S11 in the thickness direction. Specifically, each of the plurality of recesses 5A to 5D is more recessed than the plurality of outer bulges 4A to 4D in the thickness direction. In other words, each of the plurality of outer bulges 4A to 4D bulges out more than the plurality of recesses 5A to 5D. A plurality of recesses 5A to 5D are formed on the outer surface S12. That is, the outer surface S12 has a plurality of recesses 5A to 5D.

(1-4) Inner bulge 6
As shown in FIG. 4, the inner bulge 6 is arranged on the inner surface S11 of the side wall 2. As shown in FIG. The inner bulge 6 is arranged between the edge 3A and the edge 3B in the first direction. The inner bulging portion 6 swells inward from the edge 3A and the edge 3B in the thickness direction. When the battery cover 1 is attached to the battery 100 (see FIG. 8B), the inner bulging portion 6 swells from the edge 3A and the edge 3B toward the side surface S3 of the battery 100 in the thickness direction.

As shown in FIG. 5, the inner bulge 6 is arranged from the first side wall 2A to the fourth side wall 2D.

(2) Layered Structure of Battery Cover 1 As shown in FIGS. 4 and 5, the battery cover 1 includes a first surface layer 11, a second surface layer 12, a heat insulating layer 13, and a cushion layer 14. In other words, the side wall 2 includes a first surface layer 11 , a second surface layer 12 , a heat insulating layer 13 , and a cushion layer 14 .

(2-1) First surface layer 11
The first surface layer 11 is the innermost layer of the side wall 2 in the thickness direction. When the battery cover 1 is attached to the battery 100 (see FIG. 8B), the first surface layer 11 is insulated between the side surface S3 of the battery 100 and the cushion layer 14 or with the side surface S3 of the battery 100 in the thickness direction. layer 13. The first surface layer 11 protects the heat insulating layer 13 and the cushion layer 14 on the inner side in the thickness direction. The first surface layer 11 is arranged on the entire side wall 2. With the battery cover 1 attached to the battery 100, the first surface layer 11 contacts the side surface S3 of the battery 100. The first surface layer 11 has an inner surface S11.

Examples of the material for the first surface layer 11 include nonwoven fabric, woven fabric, plastic sheet, and plastic film.

Materials for nonwoven fabrics and textiles include, for example, natural fibers such as cotton, linen, pulp, wool, silk, and mineral fibers, such as polyester fibers, polyethylene fibers, polypropylene fibers, nylon fibers, aramid fibers, acrylic fibers, vinylon fibers, Examples include chemical fibers such as rayon and glass fiber. Nonwoven fabrics and woven fabrics may be made of a single type of fiber, or may be made of multiple types of fiber.

Examples of materials for the plastic sheet and plastic film include thermosetting resins such as polyester resins, polyurethane resins, and polycarbonate resins, and thermoplastic resins such as polyolefin resins, polyvinyl chloride, and styrene-butadiene rubber. The plastic sheet and the plastic film may be made of a single type of resin or may be made of multiple types of resin.

The first surface layer 11 is preferably made of nonwoven fabric. When the first surface layer 11 is made of a nonwoven fabric, the material of the nonwoven fabric preferably includes chemical fibers, more preferably polyester fibers and polypropylene fibers, and even more preferably polyethylene terephthalate (PET) fibers and polyethylene terephthalate (PET) fibers. Examples include polypropylene fibers.

When the first surface layer 11 contains polyethylene terephthalate fibers, the heat resistance of the first surface layer 11 can be improved. When the first surface layer 11 contains polypropylene fibers, the first surface layer 11 can be easily thermally welded to the second surface layer 12. When the first surface layer 11 contains polyethylene terephthalate fibers and polypropylene fibers, both the heat resistance of the first surface layer 11 and the thermal weldability of the first surface layer 11 to the heat insulating layer 13 or the second surface layer 12 can be achieved.

The method for manufacturing the nonwoven fabric is not limited. Examples of methods for producing nonwoven fabric include fleece forming methods such as dry method, wet method, spunbond method, and melt blow method; for example, thermal bond method, chemical bond method, stitch bond method, needle punch method, spunlace method, and steam forming method. Examples include fleece bonding methods such as the jet method.

The nonwoven fabric may be impregnated with resin. The resin with which the nonwoven fabric is impregnated is not limited. Examples of the resin impregnated into the nonwoven fabric include thermosetting resins such as phenol resin and resilcinol resin, vinyl acetate resins such as ethylene vinyl acetate (EVA), and olefin resins such as amorphous polyolefin (APAO). Examples include thermoplastic resins such as.

Further, the nonwoven fabric may be a laminate of a resin layer and a fiber layer. Examples of the resin layer include a layer made of the vinyl acetate resin described above. Examples of the fibrous layer include layers made of the above-mentioned nonwoven and woven materials. Specifically, vinyl acetate resin, polyester fiber (more specifically, polyethylene terephthalate fiber), and polypropylene fiber are combined into vinyl acetate resin (resin layer), polyester fiber (fiber layer), and polypropylene fiber (fiber layer). ) and vinyl acetate resin (resin layer) are laminated in this order.

The thickness of the first surface layer 11 is thinner than the thickness of the heat insulating layer 13 and the cushion layer 14. The thickness of the first surface layer 11 is, for example, 0.01 mm or more, preferably 0.1 mm or more, and is, for example, 10.0 mm or less, preferably 5.0 mm or less.

(2-2) Second surface layer 12
The second surface layer 12 is the outermost layer of the side wall 2 in the thickness direction. The second surface layer 12 is arranged on the opposite side of the first surface layer 11 with respect to the heat insulating layer 13 and the cushion layer 14 in the thickness direction. The second surface layer 12 protects the heat insulating layer 13 and the cushion layer 14 on the outside in the thickness direction. With the battery cover 1 attached to the battery 100 (see FIG. 8B), the second surface layer 12 is arranged on the side opposite to the side surface S3 of the battery 100 with respect to the first surface layer 11 in the thickness direction. The second surface layer 12 is arranged on the entire side wall 2. The second surface layer 12 has an outer surface S12. The second surface layer 12 is bonded to the first surface layer 11 at the edge 3A and the edge 3B.

The second surface layer 12 may be made of the same material as the first surface layer 11 . Note that the second surface layer 12 may be made of the same material as the first surface layer 11 or may be made of a different material from the first surface layer 11.

The thickness of the second surface layer 12 is thinner than the thickness of the heat insulating layer 13 and the cushion layer 14. The thickness of the second surface layer 12 is, for example, 0.01 mm or more, preferably 0.1 mm or more, and is, for example, 10.0 mm or less, preferably 5.0 mm or less. Note that the thickness of the second surface layer 12 may be the same as the thickness of the first surface layer 11 or may be different from the thickness of the first surface layer 11.

(2-3) Heat insulation layer 13
The heat insulating layer 13 is arranged between the first surface layer 11 and the second surface layer 12 in the thickness direction. The heat insulating layer 13 is arranged between the cushion layer 14 and the second surface layer 12 in the thickness direction. A heat insulating layer 13 is disposed within each outer bulge 4A to 4D. In this embodiment, the heat insulating layer 13 is arranged in each of the outer bulges 4A to 4D and each of the recesses 5A to 5C. The heat insulating layer 13 is bonded to the second surface layer 12. The heat insulating layer 13 is made of a heat insulating material.

Examples of the heat insulating material include foamed heat insulating materials such as urethane foam, phenol foam, polyethylene foam, and polystyrene foam, glass wool, rock wool, nonwoven fabric containing silica airgel, and fibrous heat insulating materials such as cellulose fiber.

The heat insulating layer 13 is preferably made of a foam heat insulating material, more preferably urethane foam.

The thermal conductivity of the heat insulating layer 13 is 0.045 W/(m·K) or less, preferably 0.043 W/(m·K) or less, more preferably 0.040 W/(m·K) or less, and Preferably it is 0.035 W/(m·K) or less, more preferably 0.033 W/(m·K) or less, still more preferably 0.030 W/(m·K) or less, for example, 0.030 W/(m·K) or less. 015W/(m·K) or more. Thermal conductivity is measured by a hot wire method (probe method) in accordance with JIS R 2616:2001 or ASTM D 5930. Specifically, the thermal conductivity is measured at room temperature using a rapid thermal conductivity meter (manufactured by Kyoto Electronics Industry Co., Ltd., trade name "QTM-500"). The thermal conductivity of the heat insulating layer 13 is the main factor that affects the heat insulating properties of the battery cover 1. The heat insulation properties of the battery cover 1 can be evaluated by the method described in Examples described later.

Here, other factors that influence the heat insulation properties of the battery cover 1 include, for example, the thermal conductivity of the cushion layer 14, the air permeability of the heat insulation layer 13, and the air permeability of the cushion layer 14, which will be described later. If the air permeability of the heat insulating layer 13 is too high, it will be difficult for the battery cover 1 to block high-temperature airflow, and the heat insulating properties of the battery cover 1 will tend to decrease.

The air permeability of the heat insulating layer 13 is preferably lower than that of the cushion layer 14. More preferably, the air permeability of the heat insulating layer 13 is lower than that of the first surface layer 11, the second surface layer 12, and the cushion layer 14. Note that air permeability can be measured by the B method defined in JIS K 6400-7:2012 for foams, and by the Frazier method defined by JIS L 1913:2010 for nonwoven fabrics.

The air permeability of the heat insulating layer 13 is, for example, 160 ml/cm ² /sec or less, preferably 100 ml/cm ² /sec or less, more preferably 75 ml/cm ² /sec or less. When the air permeability of the heat insulating layer 13 is below the above upper limit value, it is possible to suppress the heat insulating properties of the battery cover 1 from decreasing.

The heat insulating layer 13 is harder than the cushion layer 14. The 50% compression hardness of the heat insulating layer 13 is higher than the 50% compression hardness of the cushion layer 14. The 50% compression hardness is measured in accordance with JIS K 6767:1999. Specifically, the dimensions (width x length) of the test piece used to measure the 50% compression hardness are 100 mm x 100 mm. 50% compression hardness is measured by placing a test piece between parallel flat plates of a testing machine, compressing it by 50% of the initial thickness at a compression speed of 5 mm/min, stopping, and measuring immediately after stopping the compression. It is calculated by the following formula based on the applied load P.

Formula: 50% compression hardness = Load P÷ Area of test piece (100mm x 100mm)
The 50% compression hardness of the heat insulating layer 13 is, for example, 10.0 kPa or more, preferably 11.0 kPa or more, and more preferably 12.0 kPa or more. When the 50% compression hardness of the heat insulating layer 13 is equal to or greater than the above lower limit value, it is possible to suppress deformation of the heat insulating layer 13 after the forming process described below. Note that the upper limit of the 50% compression hardness of the heat insulating layer 13 is not limited as long as the insulating layer 13 can be compressed in the molding process described later.

The compression hardness retention rate of the heat insulating layer 13 after 120 seconds is, for example, less than 75%, preferably 70% or less, and, for example, 10% or more.

The compression hardness retention rate after 120 seconds is measured by the method described in Examples below.

The compression hardness retention rate of the heat insulating layer 13 after 120 seconds is below the above upper limit (that is, the compression hardness tends to decrease in the compressed state and is difficult to recover from the compressed state), which will be described later. After the molding process, deformation of the heat insulating layer 13 can be suppressed. Thereby, the shapes of the recesses 5A to 5C and a recess 40 (see FIG. 10) in a modified example to be described later can be maintained. Therefore, the side wall 2 can be bent at the recesses 5A to 5C so that the recesses 5A to 5D follow the corners C1 to C4 of the battery 100. As a result, the battery cover 1 can be easily attached to the battery-100. Further, the recess 40 can suppress interference between the side wall 2 and the member M (see FIG. 10) arranged around the battery 100.

When the battery cover 1 is removed from the battery 100, the thickness of the heat insulating layer 13 in each of the outer bulges 4A to 4D is, for example, 3 mm or more, preferably 5 mm or more, and, for example, 25 mm or less, preferably, It is 20 mm or less. Since the thickness of the heat insulating layer 13 in each of the outer bulges 4A to 4D is equal to or greater than the above lower limit, the heat insulating properties of the battery cover 1 can be ensured. By setting the thickness of the heat insulating layer 13 in each of the outer bulges 4A to 4D to be less than or equal to the above upper limit, it is possible to prevent the battery cover 1 from becoming excessively large.

When the battery cover 1 is removed from the battery 100, the thickness of the heat insulating layer 13 in each of the recesses 5A to 5C is thinner than the thickness of the heat insulating layer 13 in each of the outer bulges 4A to 4D. Specifically, the thickness of the heat insulating layer 13 in each of the recesses 5A to 5C is, for example, 10 mm or less, preferably 5 mm or less, and, for example, 1 mm or more. Since the thickness of the heat insulating layer 13 in each of the recesses 5A to 5C is thinner than the thickness of the heat insulating layer 13 in each of the outer bulges 4A to 4D, the side wall 2 can be easily bent in each of the recesses 5A to 5C. By bending the side wall 2 at each of the recesses 5A to 5C, the side wall 2 can be aligned with the side surface S3 of the battery 100.

When the battery cover 1 is removed from the battery 100, the density of the heat insulating layer 13 in each of the outer bulges 4A to 4D is, for example, 100 kg/m ³ or less, preferably 50 kg/m ³ or less, and, for example, It is 1 kg/m ³ or more, preferably 10 kg/m ³ or more. Density is measured in accordance with JIS A 9521:2017 or JIS K 6767:1999. By setting the density to be less than or equal to the above upper limit, thermal conductivity can be reduced.

When the battery cover 1 is removed from the battery 100, the heat insulating layer 13 in each of the recesses 5A to 5C is more compressed in the thickness direction than the insulating layer 13 in each of the outer bulges 4A to 4D. In other words, the density of the heat insulating layer 13 in each of the recesses 5A to 5C is higher than the density of the heat insulating layer 13 in each of the outer bulges 4A to 4D. The density of the heat insulating layer 13 in each of the recesses 5A to 5C is, for example, 10 kg/m ³ or more and 70 kg/m ³ or less.

(2-4) Cushion layer 14
The cushion layer 14 is arranged between the first surface layer 11 and the heat insulating layer 13 in the thickness direction. The cushion layer 14 is arranged within the inner bulge 6 . The cushion layer 14 extends from one end of the side wall 2 to the other end in the first direction. In other words, the cushion layer 14 extends from the edge 3A to the edge 3B in the first direction. In this embodiment, the cushion layer 14 is arranged between the edge 3A and the edge 3B in the first direction. In this embodiment, the cushion layer 14 is bonded to the heat insulating layer 13.

The cushion layer 14 is elastically deformable. As will be explained later, when the battery cover 1 is attached to the battery 100 (see FIG. 8A), the cushion layer 14 is deformed (concave) to match the shape of the outer surface of the battery 100. Thereby, the battery cover 1 can be smoothly attached to the battery 100. Furthermore, when the battery cover 1 is attached to the battery 100, the cushion layer 14 is deformed, so that excessive stress can be suppressed from being applied to the heat insulating layer 13, and the heat insulating layer 13 can be protected. Further, when the battery cover 1 is attached to the battery 100 (see FIG. 8B), the elasticity of the cushion layer 14 allows the first surface layer 11 to reliably contact the side surface S3 of the battery 100. Thereby, with the battery cover 1 attached to the battery 100, the space between the side surface S3 of the battery 100 and the heat insulating layer 13 can be filled with the cushion layer 14 and the first surface layer 11. As a result, it is possible to suppress the air around the battery 100 from flowing between the side surface S3 of the battery 100 and the heat insulating layer 13, and it is possible to suppress the transfer of ambient heat to the battery 100.

Examples of the material for the cushion layer 14 include the above-mentioned heat insulating materials. The cushion layer 14 is preferably made of foam-based heat insulating material, more preferably urethane foam.

The cushion layer 14 is softer than the heat insulation layer 13. The 50% compression hardness of the cushion layer 14 is lower than the 50% compression hardness of the heat insulating layer 13. The 50% compression hardness of the cushion layer 14 is, for example, less than 10.0 kPa, preferably 8.0 kPa or less, more preferably 6.0 kPa or less, and, for example, 1.0 kPa or more, preferably 1.5 kPa. More preferably, it is 2.0 kPa or more. Since the 50% compression hardness of the cushion layer 14 is less than or equal to the above upper limit value, the cushion layer 14 can be easily deformed when the battery cover 1 is attached to the battery 100. Thereby, the battery cover 1 can be smoothly attached to the battery 100. When the 50% compression hardness of the cushion layer 14 is equal to or greater than the above lower limit, the shape of the cushion layer 14 can be maintained.

The compression hardness retention rate of the cushion layer 14 after 120 seconds is, for example, 75% or more, preferably 80% or more, and, for example, 95% or less.

The compression hardness retention rate of the cushion layer 14 after 120 seconds is equal to or higher than the above lower limit value (that is, the compression hardness is hard to decrease in a compressed state and it is easy to restore from the compressed state), so that the battery cover 1 is reliably restored when attached to the battery 100, and the space between the side surface S3 of the battery 100 and the heat insulating layer 13 can be filled.

The thermal conductivity of the cushion layer 14 is 0.045 W/(m·K) or less, preferably 0.043 W/(m·K) or less, more preferably 0.040 W/(m·K) or less, and Preferably it is 0.035 W/(m·K) or less, more preferably 0.033 W/(m·K) or less, still more preferably 0.030 W/(m·K) or less, for example, 0.030 W/(m·K) or less. 015W/(m·K) or more.

When the battery cover 1 is removed from the battery 100, the thickness of the cushion layer 14 is, for example, 1 mm or more, preferably 2 mm or more, and, for example, 7 mm or less, preferably 5 mm or less. Since the thickness of the cushion layer 14 is equal to or larger than the above lower limit value, the amount of deformation of the cushion layer 14 can be ensured when the battery cover 1 is attached to the battery 100, and the ease of attaching the battery cover 1 to the battery 100 can be ensured. can be improved. By setting the thickness of the cushion layer 14 to be less than or equal to the above upper limit value, it is possible to prevent the battery cover 1 from becoming excessively large.

3. Method for Manufacturing Battery Cover 1 Next, a method for manufacturing battery cover 1 will be described with reference to FIGS. 6A to 7.

In this embodiment, the method for manufacturing the battery cover 1 includes a lamination process (see FIG. 6A) and a molding process (see FIG. 6B).

As shown in FIG. 6A, in the lamination process, the first surface layer 11, the cushion layer 14, the heat insulation layer 13, and the second surface layer 12 are stacked in the thickness direction. 12 to obtain a laminate 21.

Here, the first surface layer 11 and the second surface layer 12 are made of vinyl acetate resin, polyester fiber (more specifically, polyethylene terephthalate fiber), and polypropylene fiber, vinyl acetate resin (resin layer), polyester fiber ( In the case of a nonwoven fabric in which a fiber layer), a polypropylene fiber (fiber layer), and a vinyl acetate resin (resin layer) are laminated in this order, the polypropylene fibers of the first surface layer 11 are stacked in the thickness direction of the laminate 21 in the first surface layer. 11 polyethylene terephthalate fibers and the cushion layer 14. Further, the polypropylene fibers of the second surface layer 12 are arranged between the polyethylene terephthalate fibers of the second surface layer 12 and the heat insulating layer 13 in the thickness direction of the laminate 21 .

The laminate 21 has a flat band shape extending in a predetermined direction. The laminate 21 has one end E1 and the other end E2 in the direction in which the laminate 21 extends.

In addition, between the first surface layer 11 and the second surface layer 12 in the peripheral portion of the laminate 21 (the portion where the edge portion 3A and the edge portion 3B are formed, and the one end portion E1 and the other end portion E2), the second surface layer Adhesive tape or adhesive is placed between the cushion layer 12 and the heat insulating layer 13 and between the cushion layer 14 and the heat insulating layer 13, if necessary. Examples of the adhesive include hot melt adhesives that can be bonded by heating.

Next, as shown in FIGS. 6B and 7, in the molding process, the first surface layer 11 and the second surface layer 12 are bonded at the peripheral edge of the laminate 21 by hot pressing the laminate 21, and a predetermined shape is formed. Recesses 5A to 5C are formed at the respective positions. Each of the recesses 5A to 5C is formed by compressing the heat insulating layer 13.

Thereafter, the laminate 21 is bent at each of the recesses 5A to 5C to connect one end E1 and the other end E2 of the laminate 21. Then, as shown in FIG. 3, the battery cover 1 is completed. Note that the recess 5D is formed by connecting one end E1 and the other end E2.

4. Attaching Battery Cover 1 to Battery 100 Next, attachment of battery cover 1 to battery 100 will be described with reference to FIGS. 8A and 8B.

As shown in FIG. 8A, in this embodiment, the battery cover 1 is attached to the battery 100 placed on a predetermined plane from above (one side in the first direction).

At this time, in the conventional battery cover, if there is a protruding part P (for example, the edge of the lid 102 of the battery 100) on the side surface S3 of the battery 100, the inner surface of the battery cover gets caught on the protruding part P, and the battery cover It may prevent you from wearing it.

In this regard, the battery cover 1 has a cushion layer 14 covered with the first surface layer 11 on the inner surface S11.

Therefore, when the battery cover 1 is attached to the battery 100, when the inner surface S11 of the battery cover 1 comes into contact with the protruding part P, the part of the battery cover 1 that comes into contact with the protruding part P (hereinafter referred to as the contact part). In this case, the cushion layer 14 is deformed (concave).

Then, as the battery cover 1 moves downward, the cushion layer 14 deforms in order at the contact portion, and the first surface layer 11 slides against the protruding portion P.

Thereby, the battery cover 1 can smoothly get over the protruding portion P. In the portion of the battery cover 1 that has climbed over the protruding portion P, the cushion layer 14 is restored due to its elasticity.

Then, as shown in FIG. 8B, when the entire battery cover 1 climbs over the protruding portion P, the cushion layer 14 is restored over the entire battery cover 1, and the first surface layer 11 is pushed by the cushion layer 14 and the battery 100 comes into contact with the side surface S3. With the battery cover 1 attached to the battery 100, the space between the side surface S3 of the battery 100 and the heat insulating layer 13 is filled with the cushion layer 14 and the first surface layer 11.

Through the above steps, attachment of the battery cover 1 to the battery 100 is completed.

5. Effects (1) According to the battery cover 1, as shown in FIG. 8B, the first surface layer 11 is in contact with the side surface S3 of the battery 100, and the cushion layer is arranged between the first surface layer 11 and the heat insulating layer 13. 14.

As shown in FIG. 8A, when the battery cover 1 is attached to the battery 100, the side wall 2 of the battery cover 1 slides on the first surface layer 11 against the side surface S3 of the battery 100.

At this time, even if there is a protrusion P on the side surface S3 of the battery 100, the cushion layer 14 disposed inside the side wall 2 (between the first surface layer 11 and the heat insulating layer 13) is recessed to fit the protrusion P ( By elastically deforming), it is possible to suppress the first surface layer 11 from being caught on the protruding portion P.

Thereby, even if there is a protrusion P on the side surface S3 of the battery 100, the battery cover 1 can smoothly get over the protrusion P.

As a result, the battery cover 1 can be smoothly attached to the battery 100.

Further, as shown in FIG. 8B, when the battery cover 1 is completely attached to the battery 100, the elasticity of the cushion layer 14 allows the first surface layer 11 to reliably contact the side surface S3 of the battery 100.

Thereby, the space between the side surface S3 of the battery 100 and the heat insulating layer 13 can be filled with the cushion layer 14 and the first surface layer 11.

As a result, it is possible to suppress the air around the battery 100 from flowing between the side surface S3 of the battery 100 and the heat insulating layer 13, and it is possible to suppress the transfer of ambient heat to the battery 100.

(2) According to the battery cover 1, the 50% compression hardness of the cushion layer 14 is lower than the 50% compression hardness of the heat insulating layer 13.

Therefore, the cushion layer 14 can be easily deformed while maintaining the shape of the heat insulating layer 13.

(3) According to the battery cover 1, the 50% compression hardness of the heat insulating layer 13 is 10.0 kPa or more, and the 50% compression hardness of the cushion layer 14 is 1.0 kPa or more and less than 10.0 kPa.

Therefore, it is possible to more easily deform the cushion layer 14 while maintaining the shape of the heat insulating layer 13 more easily.

(4) According to the battery cover 1, the thermal conductivity of the heat insulating layer 13 is 0.045 W/(m·K) or less.

Therefore, the heat insulating layer 13 can suppress the transfer of ambient heat to the battery 100.

(5) According to the battery cover 1, each of the heat insulating layer 13 and the cushion layer 14 is made of a foam-based heat insulating material or a fiber-based heat insulating material.

Therefore, the battery cover 1 can be easily attached to the battery 100, and the heat insulation properties can be improved.

(6) According to the battery cover 1, as shown in FIG. 4, the cushion layer 14 extends from one end of the side wall 2 to the other end in the first direction.

Therefore, as shown in FIG. 8B, when the attachment of the battery cover 1 to the battery 100 is completed, there is a hole on the side surface S3 of the battery 100 from one end to the other end of the side wall 2 of the battery cover 1 in the first direction. 1 surface layer 11 can be brought into contact with each other reliably.

(7) According to the battery cover 1, as shown in FIGS. 3 and 5, the outer surface S12 of the side wall 2 has recesses 5A to 5C that are recessed in the thickness direction, and an outer bulge that is larger than the recesses 5A to 5C in the thickness direction. It has sections 4A to 4D.

Therefore, the side wall 2 can be easily bent in the recesses 5A to 5C while ensuring heat insulation in the outer bulges 4A to 4D.

(8) According to the battery cover 1, when the battery cover 1 is removed from the battery 100, as shown in FIG. It is thinner than the thickness of the heat insulating layer 13.

Therefore, by molding the heat insulating layer 13, the recesses 5A to 5C can be formed while ensuring the thickness of the cushion layer 14.

(9) According to the battery cover 1, when the battery cover 1 is removed from the battery 100, as shown in FIG. It is more compressed than the heat insulating layer 13 in 4D.

Therefore, by compressing the heat insulating layer 13, the recesses 5A to 5C can be easily formed.

(10) According to the battery cover 1, the recesses 5A to 5C extend along the corners C1 to C3 of the battery 100, as shown in FIG.

Therefore, the side wall 2 can be bent according to the corners C1 to C3 of the battery 100, and the side wall 2 can be made to follow the side surface S3 of the battery 100.

6. Modification Examples Modification examples of the battery cover 1 will be described below. In the description of the modification, the same members as those in the above-described embodiment are given the same reference numerals, and the description thereof will be omitted.

(1) As shown in FIGS. 9A and 9B, the battery cover 30 does not need to have the edges 3A, 3B and the recesses 5A to 5D.

(2) The shape of the battery cover is not limited. The shape of the battery cover can be changed as appropriate depending on the shape of the battery. For example, if the battery has a shape without corners, such as a cylindrical shape, the battery cover may have a cylindrical shape. Further, when the battery has a flat shape such as a flat plate shape, the battery cover may have a first side wall and a second side wall, and the battery may be sandwiched between the first side wall and the second side wall.

(3) The corners C1 to C4 of the battery 100 may be curved surfaces. In this case, the recesses 5A to 5D may lie along a curved surface.

(4) The recesses 5A to 5C may be formed from the first surface layer 11 and the second surface layer 12. The heat insulating layer 13 and the cushion layer 14 may not be provided in the recesses 5A to 5C.

(5) As shown in FIG. 10, the battery cover 1 may have a recess 40 to avoid interference between the side wall 2 and the member M arranged around the battery 100.

(6) As shown in FIG. 11, the cushion layer 14 may be present only at both ends of the side wall 2 in the vertical direction.

(7) The above-described modifications can be combined as appropriate.

Next, the present invention will be explained based on Examples and Comparative Examples. The invention is not limited by the examples below. In addition, specific numerical values of physical property values, parameters, etc. used in the following description are the corresponding upper limit values of physical property values, parameters, etc. described in the above "Detailed Description" It can be replaced by a lower limit value (a numerical value defined as "less than" or "less than") or a lower limit value (a numerical value defined as "greater than or equal to").

1. Preparation of materials The following materials were prepared.

(1) TF1100R (urethane foam, manufactured by Wm.T.Burnett & co.)
(2) UEI-3 (urethane foam, manufactured by INOAC Corporation)
(3) F2 (urethane foam, manufactured by INOAC Corporation)
2. Measurement of physical properties of materials (1) Thermal conductivity The thermal conductivity of each of the above materials was measured at room temperature using a rapid thermal conductivity meter (manufactured by Kyoto Electronics Industry Co., Ltd., trade name "QTM-500").

(2) 50% compression hardness The 50% compression hardness of each material was measured using a testing machine (manufactured by Shimadzu Corporation, trade name "AG-XPlus").

Place the test piece (width: 100 mm, length: 100 mm) between the parallel plane plates of the testing machine, compress it by 50% of the initial thickness at a compression speed of 5 mm/min, then stop, and immediately after stopping the compression. The load P was measured. Based on the obtained load P, 50% compression hardness H1 was calculated using the following formula.

Formula: 50% compression hardness = Load P÷ Area of test piece (100mm x 100mm)
(3) Compression hardness retention rate after 120 seconds The compression hardness retention rate of each material after 120 seconds was measured using a testing machine (manufactured by Shimadzu Corporation, trade name "AG-XPlus").

Place the test piece (width: 100 mm, length: 100 mm) between the parallel plane plates of the testing machine, compress it by 50% of the initial thickness at a compression speed of 5 mm/min, then stop, and immediately after stopping the compression. The load P was measured.

Next, the test piece was held as it was (compressed by 50% of the initial thickness) for 120 seconds, and the load P2 was measured 120 seconds after the load P was measured.

Based on the obtained load P, the 50% compression hardness H1 was calculated using the above formula, and based on the obtained load P2, the 50% compression hardness H2 after holding for 120 seconds was calculated using the above formula. .

The percentage of the 50% compression hardness H2 to the 50% compression hardness H1 (H2÷H1×100) is the compression hardness retention rate after 120 seconds.

3. Manufacturing of battery cover Example 1
A first surface layer, a cushion layer shown in Table 1, a heat insulation layer shown in Table 1, and a second surface layer are laminated in the order of the first surface layer, the cushion layer, the heat insulation layer, and the second surface layer in the thickness direction to form a laminate. (Lamination process, see FIG. 6A). The first surface layer and the second surface layer are made of nonwoven fabric (vinyl acetate resin, polyethylene terephthalate fiber, and polypropylene fiber (base fabric)), vinyl acetate resin (basis weight 8 g/m ² ), polyethylene terephthalate fiber (basis weight 80 g/m 2 ), m ² ), polypropylene fiber (fabric weight 17 g/m ² ), and vinyl acetate resin (fabric weight 8 g/m ² ). The polypropylene fibers of the first surface layer are arranged between the polyethylene terephthalate fibers of the first surface layer and the cushion layer in the thickness direction of the laminate. Moreover, the polypropylene fibers of the second surface layer are arranged between the polyethylene terephthalate fibers of the second surface layer and the heat insulating layer in the thickness direction of the laminate. Note that adhesive tape (trade name "TW-Y01", manufactured by Nitto Denko Corporation) was placed between the second surface layer and the heat insulating layer and between the cushion layer and the heat insulating layer.

Next, the laminate was hot pressed (molding process, see FIG. 6B). The first surface layer and the second surface layer were thermally welded at the peripheral edge of the laminate to form an edge. Furthermore, a recess was formed at a predetermined position by compressing the heat insulating layer. Further, the second surface layer and the heat insulating layer were bonded together using adhesive tape, and the cushion layer and the heat insulating layer were bonded together using adhesive tape.

As a result, a battery cover sample was obtained.

Examples 2 and 3 and Comparative Examples 1 to 3
A battery cover sample was obtained in the same manner as in Example 1, except that the heat insulating layer and cushion layer were replaced with the heat insulating layer and cushion layer shown in Table 1.

4. Performance evaluation of battery cover (1) Heat insulation <shape of test piece>
Test piece A was cut from the samples obtained in each of the above-mentioned Examples and Comparative Examples.

As shown in FIG. 12, test piece A is square. Test piece A has a bulge 4 and a recess 5.

The bulge 4 is arranged at the center of the test piece A. The bulge 4 has a square shape. The length L of one side of the bulge portion 4 is 240 mm. As shown in FIG. 13, the thickness T of the bulge portion 4 is 10 mm.

As shown in FIG. 12, the recess 5 is arranged around the bulge 4. As shown in FIG. The width W of the recess 5 is 10 mm.

<Configuration of evaluation device>
As shown in FIG. 14, the evaluation device 110 includes a constant temperature bath 111, a jig 112, a temperature sensor 113, a cable 114, and a data logger 115.

The constant temperature bath 111 includes a fan 116. As the constant temperature bath 111, "SH-242" manufactured by Espec was used.

The jig 112 is placed inside the constant temperature bath 111. The jig 112 faces the fan 116 at an interval in the opposing direction. The opposing direction is a direction in which the jig 112 and the fan 116 face each other. The jig 112 is made of a phenolic resin foam (trade name "Neoma Foam", manufactured by Asahi Kasei Kenzai Co., Ltd.) with a thickness of 9 mm. The jig 112 has a housing 112A and a flange 112B.

The housing 112A has one end and the other end in opposing directions. One end is disposed between the fan 116 and the other end in the opposing direction. As shown in FIG. 15, the housing 112A is square when viewed from the opposite direction. The outer dimension L11 of the housing 112A is 240 mm. The depth (inner dimension in the opposing direction) L12 (see FIG. 14) of the housing 112A is 50 mm. The housing 112A has an opening 112C.

As shown in FIG. 14, the opening 112C is arranged at one end of the housing 112A in the opposing direction. As shown in FIG. 15, the opening 112C is square when viewed from the opposite direction. The dimension L13 of one side of the opening 112C is 220 mm.

As shown in FIG. 14, the flange 112B extends from one end of the housing 112A in the opposing direction. The flange 112B extends in a direction perpendicular to the opposing direction. The flange 112B has a flat plate shape. As shown in FIG. 15, the outer shape of the jig 112 including the flange 112B is square when viewed from the opposing direction. The outer dimension L14 of the jig 112 including the flange 112B is 260 mm.

As shown in FIG. 14, the test piece A described above is fixed to a jig 112. With the test piece A fixed to the jig 112, the bulge 4 of the test piece A closes the opening 112C of the jig 112. With the test piece A fixed to the jig 112, the distance D1 between the test piece A and the fan 116 is 150 mm.

Temperature sensor 113 measures the temperature inside casing 112A. As the temperature sensor 113, a K thermocouple defined in JIS C 1602:2015 was used. Temperature sensor 113 is arranged within housing 112A. The temperature sensor 113 is arranged at the center of the housing 112A in the opposing direction and at the center of the housing 112A in the direction orthogonal to the corresponding direction.

Cable 114 electrically connects temperature sensor 113 and data logger 115. One end of the cable 114 is electrically connected to the temperature sensor 113 through a through hole 112D provided in the wall of the housing 112A. Note that the through hole 112D through which the cable 114 passes is filled with clay or the like. The other end of the cable 114 is electrically connected to a data logger 115.

Data logger 115 records the temperature measured by temperature sensor 113.

<Evaluation method of insulation>
The heat insulation properties of the test piece A described above were evaluated using the evaluation apparatus 110 described above. Specifically, from a state where the temperature inside the thermostatic oven 111 was at room temperature (25° C.), the temperature within the thermostatic oven 111 was set to 90° C., and the thermostatic oven 111 was operated at a constant temperature, and the temperature change inside the housing 112A was measured. From the obtained measurement results, the heat insulation properties of the test piece A of each Example and each Comparative Example were evaluated based on the following evaluation criteria. The results are shown in Table 1.

In addition, in Comparative Example 2, the air permeability of the heat insulating layer was excessively high, and the ability to block the airflow generated by the rotation of the fan 116 was low, so it is considered that the heat insulating property was poor.

<Evaluation criteria>
Good: The temperature inside the jig 112 is less than 65° C. 10 minutes after the constant temperature operation of the constant temperature bath 111 is started.

×: The temperature inside the jig 112 is 65° C. or higher 10 minutes after the constant temperature operation of the constant temperature bath 111 is started.

(2) Wearability <Shape of test piece>
Test piece B was cut from the samples obtained in each of the Examples and Comparative Examples described above.

As shown in FIG. 16, test piece B is rectangular. Test piece B has a bulge 4 and a recess 5.

The bulging portion 4 is arranged at the center of the test piece B in the longitudinal direction of the test piece B. The bulging portion 4 extends in the width direction of the test piece B. The width direction of test piece B is perpendicular to the longitudinal direction of test piece B. The length L21 of the bulge 4 in the longitudinal direction of the test piece B is 50 mm. The length L22 of the bulge portion 4 in the width direction of the test piece B is 100 mm. Note that the thickness of the bulging portion 4 is 10 mm, which is the same as the thickness T of the test piece A described above.

The recess 5 is arranged around the bulge 4 . The width W1 of the recess 5 in the longitudinal direction of the test piece B is 150 mm. The width W2 of the recess 5 in the width direction of the test piece B is 10 mm.

<Configuration of evaluation device>
As shown in FIG. 17, the evaluation device 200 includes two plates 201A and 201B and two supports 202A and 202B.

The plate 201B faces the plate 201A with an interval in the opposing direction. The opposing direction is a direction in which the plate 201A and the plate 201B face each other. Each of the plates 201A and 201B extends in a direction perpendicular to the opposing direction. The distance D2 between the plates 201A and 201B in the opposing direction is 7 mm, which is shorter than the thickness of the bulge 4 of the test piece B (see FIG. 16). Each of the plates 201A and 201B is made of polypropylene.

The support column 202A supports the plate 201A. The support column 202A is located on the opposite side of the plate 201B from the plate 201A in the opposing direction.

Post 202B supports plate 201B. The support column 202B is located on the opposite side of the plate 201A with respect to the plate 201B in the opposing direction.

<Evaluation method for wearability>
Using the evaluation device 200 described above, the wearability of the test piece B described above was evaluated. Specifically, as shown in FIG. 18, one end of the test piece B in the longitudinal direction was placed between the plates 201A and 201B. At this time, one surface of the test piece B in the thickness direction faces the plate 201A, and the other surface of the test piece B in the thickness direction faces the plate 201B.

Next, the test piece B was pulled in the longitudinal direction, and the wearability of the test piece B of each Example and each Comparative Example was evaluated based on the following evaluation criteria. The results are shown in Table 1.

<Evaluation criteria>
Good: The bulging portion 4 was able to pass between the plates 201A and 201B.

×: The bulging portion 4 could not pass between the plate 201A and the plate 201B.

1 Battery cover 2 Side wall 4A to 4D Outer bulge 5A to 5D Recess 11 First surface layer 12 Second surface layer 13 Heat insulation layer 14 Cushion layer 30 Battery cover 40 Recess 100 Battery C1 to C4 Corner S1 First surface S2 Second surface S3 Side S11 Inner surface S12 Outer surface

Claims (10)

Equipped with a side wall that covers the sides of the battery,
The side wall is
a first surface layer in contact with the side surface of the battery;
a second surface layer disposed on the opposite side of the side surface of the battery with respect to the first surface layer in the thickness direction of the side wall;
a heat insulating layer disposed between the first surface layer and the second surface layer in the thickness direction;
A battery cover comprising: a cushion layer disposed between the first surface layer and the heat insulating layer in the thickness direction. The battery cover of claim 1, wherein a 50% compression hardness of the cushion layer is lower than a 50% compression hardness of the heat insulation layer. The 50% compression hardness of the heat insulating layer is 10.0 kPa or more,
The battery cover according to claim 2, wherein the cushion layer has a 50% compression hardness of 1.0 kPa or more and less than 10.0 kPa. The battery cover according to any one of claims 1 to 3, wherein the thermal conductivity of the heat insulating layer is 0.045 W/(m·K) or less. The battery cover according to claim 1, wherein each of the heat insulating layer and the cushion layer is made of a fiber-based heat insulating material or a foam-based heat insulating material. The battery has a first surface on which a terminal is disposed, a second surface spaced apart from the first surface in a first direction, and arranged between the first surface and the second surface in the first direction. , the side surface extending in the first direction,
The battery cover according to claim 1, wherein the cushion layer extends from one end of the side wall to the other end in the first direction. The side wall has an inner surface that contacts the side surface of the battery in the thickness direction, and an outer surface that is disposed on the opposite side of the side surface of the battery with respect to the inner surface in the thickness direction,
The outer surface is
a recessed portion recessed in the thickness direction;
The battery cover according to any one of claims 1 to 6, further comprising a bulging portion that bulges out more than the recessed portion in the thickness direction. The battery cover according to claim 7, wherein when the battery cover is removed from the battery, the thickness of the heat insulating layer in the recess is thinner than the thickness of the heat insulating layer in the bulge. . 8. The heat insulating layer in the recess is more compressed in the thickness direction than the heat insulating layer in the bulge when the battery cover is removed from the battery. Battery cover described in 8. The battery cover according to any one of claims 7 to 9, characterized in that the recess extends along a corner of the battery.

Images